U.S. patent application number 11/166429 was filed with the patent office on 2007-01-18 for cementitious block material utilizing spent blasting abrasive particles.
This patent application is currently assigned to U.S. TECHNOLOGY CORPORATION. Invention is credited to Raymond F. Williams.
Application Number | 20070012219 11/166429 |
Document ID | / |
Family ID | 37660495 |
Filed Date | 2007-01-18 |
United States Patent
Application |
20070012219 |
Kind Code |
A1 |
Williams; Raymond F. |
January 18, 2007 |
Cementitious block material utilizing spent blasting abrasive
particles
Abstract
An accelerated-curing concrete masonry unit (CMU) mixture
includes aggregate material, hydraulic cement and spent blasting
abrasive particles, and may also include paint residue particles.
The abrasive particles or abrasive and paint particles combined
preferably make up at least 5.0% of the mixture by volume.
Preferably, the hydraulic cement is Portland cement and the
abrasive or combined particles make up about 10.0% to 17.0% of the
mixture by volume. The abrasive particles typically have a fineness
modulus ranging from 0.6 to 1.5 and more preferably from 0.75 to
1.2. Plastic particles may make up some or all of the abrasive
particles. CMUs formed with this mixture are substantially more
water repellent than standard CMUs and have a water absorption
often no greater than 9.0 pounds per cubic foot. Preferred CMUs
have an average net compressive strength of over 2,500 psi while
levels of 3,000 psi or 3,500 psi are not uncommon.
Inventors: |
Williams; Raymond F.;
(Massillon, OH) |
Correspondence
Address: |
SAND & SEBOLT
AEGIS TOWER, SUITE 1100
4940 MUNSON STREET, NW
CANTON
OH
44718-3615
US
|
Assignee: |
U.S. TECHNOLOGY CORPORATION
Canton
OH
|
Family ID: |
37660495 |
Appl. No.: |
11/166429 |
Filed: |
June 24, 2005 |
Current U.S.
Class: |
106/400 |
Current CPC
Class: |
Y02W 30/91 20150501;
C04B 28/04 20130101; Y02W 30/96 20150501; C04B 2111/27 20130101;
C04B 18/0481 20130101; C04B 18/0481 20130101; C04B 20/0076
20130101; C04B 28/04 20130101; C04B 18/0481 20130101; C04B 18/18
20130101 |
Class at
Publication: |
106/400 |
International
Class: |
C04B 14/00 20060101
C04B014/00 |
Claims
1. A concrete masonry unit (CMU) mixture comprising: aggregate
material; hydraulic cement; and a plurality of spent blasting
abrasive particles (BAPs).
2. The CMU mixture of claim 1 wherein the BAPs make up at least
5.0% of the mixture by volume.
3. The CMU mixture of claim 2 wherein the BAPs includes a plurality
of plastic particles which make up at least 5.0% of the mixture by
volume.
4. The CMU mixture of claim 1 further including a plurality of
paint residue particles (PRPs).
5. The CMU mixture of claim 4 wherein a combination of the BAPs and
the PRPs has a fineness modulus in the range of 0.6 to 1.5.
6. The CMU mixture of claim 5 wherein the mixture when cured has an
average water absorption which is no greater than 11.0 pounds per
cubic foot.
7. The CMU mixture of claim 5 wherein the combination has a
fineness modulus in the range of 0.75 to 1.2.
8. The CMU mixture of claim 4 wherein a combination of the BAPs and
the PRPs makes up from 7.0% to 17.0% of the mixture by volume.
9. The CMU mixture of claim 4 wherein a combination of the BAPs and
the PRPs makes up at least 10.0% of the mixture by volume.
10. The CMU mixture of claim 1 wherein the mixture when cured has
an average net compressive strength of at least 2,500 psi.
11. The CMU mixture of claim 10 wherein the mixture when cured has
an average net compressive strength of at least 3,000 psi.
12. The CMU mixture of claim 1 wherein the mixture when cured has
an average oven-dry density which is less than 105 pounds per cubic
foot and an average water absorption which is no greater than 15.0
pounds per cubic foot.
13. The CMU mixture of claim 12 wherein the average water
absorption is no greater than 13.0 pounds per cubic foot.
14. The CMU mixture of claim 1 wherein the mixture when cured has
an average oven-dry density ranging from 105 pounds per cubic foot
to less than 125 pounds per cubic foot and an average water
absorption which is no greater than 13.0 pounds per cubic foot.
15. The CMU mixture of claim 14 wherein the average water
absorption is no greater than 11.0 pounds per cubic foot.
16. The CMU mixture of claim 1 wherein the mixture when cured has
an average oven-dry density which is at least 125 pounds per cubic
foot and an average water absorption which is no greater than 11.0
pounds per cubic foot.
17. The CMU mixture of claim 16 wherein the average water
absorption is no greater than 10.0 pounds per cubic foot.
18. The CMU mixture of claim 1 wherein the BAPs include at least
one of acrylic, melamine formaldehyde, urea formaldehyde,
polyester, aluminum oxide, copper slag, boiler slag, coal slag,
glass, garnet, staurolite and ferric oxide.
19. The CMU mixture of claim 1 wherein the hydraulic cement is
Portland cement.
20. The CMU mixture of claim 1 wherein the hydraulic cement is one
of Portland cement and modified Portland cement in accordance with
the requirements of ASTM C-90-03.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention relates generally to cementitious block or
concrete masonry units (CMUs) and a mixture of materials forming
the CMU. More particularly, the invention relates to CMU material
which provides improved characteristics such as water repellency.
Specifically, the invention relates to such a CMU material which
includes spent blasting abrasives of a suitable size and a
sufficient amount to produce a highly desirable CMU having
increased compressive strength and substantially improved water
repellency and other characteristics.
[0003] 2. Background Information
[0004] Concrete masonry units (CMUs) have long been used in the
construction industry to provide a relatively inexpensive and
strong building unit, especially in comparison to the use of bricks
which typically have a higher cost due to the necessity of firing
the bricks to fairly high temperatures. While CMUs have been widely
used, there is still room to improve on the various characteristics
thereof. CMUs are primarily formed through the combination of
aggregates and a hydraulic cement, such as Portland cement, which
when mixed with water and allowed to cure provides a binder which
binds the aggregates together to provide the relatively strong
structural building unit. One of the detrimental characteristics of
the typical CMU is the substantial porosity thereof, which allows
water to readily be absorbed by the CMU and thereby flow through
the CMU. This of course presents a substantial issue in rainy
climates particularly where driving rain is common. In addition,
while the use of light weight aggregates has allowed for the
formation of CMUs which are of a lighter weight while maintaining a
suitable compressive strength, there is still room for improvement
in producing lighter weight CMUs. Further, there is substantial
room for economically improving the compressive strength of CMUs.
In addition, in climates which do not have a suitably high
humidity, the curing of the CMUs typically uses steam or an
artificially created high humidity environment which is heated in
order to cure the CMUs within a reasonable period of time. Thus,
there is also a need for a CMU material which will allow for the
reduction of the curing time of the CMU.
[0005] The present invention provides improvements in these areas
and other benefits which will be evident from the following
description of the invention.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention provides a concrete masonry unit (CMU)
mixture comprising aggregate material; hydraulic cement; and a
plurality of spent blasting abrasive particles.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] Preferred embodiments of the invention, illustrative of the
best modes in which applicant contemplates applying the principles,
are set forth in the following description and are shown in the
drawings and are particularly and distinctly pointed out and set
forth in the appended claims.
[0008] FIG. 1 is a perspective view of one type of concrete masonry
unit which may be formed with the material of the present
invention.
[0009] Similar numbers refer to similar parts throughout the
specification.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The concrete masonry unit (CMU) of the present invention is
indicated generally at 10 in FIG. 1. CMU 10 is a hollow
construction block which is typically approximately 8 inches by 8
inches by 16 inches. However, CMU 10 is intended to represent any
CMU, of which there are an infinitely wide variety. Typical CMUs
may be either hollow or solid and may vary in height, width and
length. Some of the typical CMUs are known by such terms as
starter, sash, half sash, solid or hollow bond beam, half height,
corner, "L" corner, and the like. Such CMUs are typically standard
blocks or split face blocks having at least one face with a more
natural looking texture for added aesthetic appeal. However, CMUs
can be made in virtually any imaginable shape with a substantial
variety of textures and configurations. The key aspect of the
present invention is the material of which CMU 10 is formed and the
advantageous properties thereof.
[0011] CMU 10 is formed of aggregate material, hydraulic cement and
in accordance with the invention, spent blasting abrasive particles
(BAPs) and paint residue particles (PRPs). As a result of the
inclusion of the BAPs or the BAPs and PRPs combined, CMU 10 is
lighter in weight, has a decreased water absorption, decreased
water penetration, allows for a substantial increase in net
compressive strength, and reduces the amount of paint needed when
it is desired that CMU 10 be painted. The use of these particles
also reduces the curing time of CMU 10. The aggregate material of
the mixture includes a broad category of materials which are
typically rocks or minerals. Some commonly used aggregate materials
are limestone, granite, basalt, sand, pumice, cinders, slag, and
gravel (such as calcareous and siliceous gravel).
[0012] As with prior art CMUs, the aggregate material of CMU 10 is
most commonly chosen from rock material within a local or regional
area. Within the industry, the aggregate material is generally
divided into the categories of coarse aggregate, fine aggregate and
light weight aggregate. The specific materials listed above
typically make up the coarse and fine aggregates. Typical light
weight aggregate is a clay, shale, slate, slag or pumice which has
been heated to a temperature sufficient to cause the material to
expand.
[0013] To insure an aggregate material which is suitably divided
into various particle sizes, the aggregate material is sorted out
by passing the material through various sieve screens, as is
typically done within the industry. A sieve analysis of the CMU
mixture is typically performed with the following number sieve
screens: 4, 8, 16, 30, 50, 80 and 100. Anything that passes through
the number 100 screen falls into a pan. The coarse aggregate is the
material retained on the number 4, number 8, and number 16 screens.
Fine aggregate is the material retained on number 30, number 50,
number 80 and number 100 screens, as well as the material in the
pan.
[0014] The hydraulic cement may be of any suitable type for forming
a CMU although Portland cement is preferred. Typically, this is a
Portland cement or modified Portland cement in accordance with ASTM
C-90, Standard Specification for Loadbearing Concrete Masonry
Units, and in particular, ASTM C-90-03, the latest version of this
standard at the time of this application. Cement usually makes up
about 6.0% to 14.0% of the CMU mixture by volume, and more
typically, about 8.0% to 12.0%. The cement to aggregate material
ratio by volume typically ranges from 1:6 to 1:12 and more
preferably from 1:7 to 1:10.
[0015] In accordance with the invention, the spent blasting
abrasive particles in the mixture are now discussed. The BAPs of
the mixture may include spent plastic blast media (PBM), which is a
soft blast media, and/or other spent blasting abrasives which are
further detailed below. The BAPs may be formed entirely of spent
PBM, entirely of one of the other blasting abrasives, or may be a
mixture of any of the PBMs and/or other abrasives. BAPs are
entrained in pressurized air for use in removing paint and the like
from aircraft or other objects. In contrast to hard blast media,
PBMs and other soft blast media are preferred for removal of paint
from aircraft and the like in order to prevent damage to the metal
structures of the aircraft during the blasting process. The BAPs
are gradually broken down into smaller sizes to the extent that
they are no longer useful as blast material. During blasting to
remove paint, the BAPs during blasting become mixed up with fine
particles of paint residue (PRPs) from the aircraft or the like.
While the spent BAPs may be separated from the PRPs, this is
typically not done, in accordance with regulations such as those of
the EPA. The vast majority of cured paints which are removed as
PRPs by such blasting are formed of a plastic material and commonly
include materials such as epoxies, polyurethanes, polyesters, gel
coats and vinyls. Most often, these are thermoset plastic
materials. The hardness of the epoxy and polyurethane PRPs on the
MOH scale typically ranges from about 2.0 to 3.0.
[0016] Currently, the types of plastic used to form PBMs are
polyester, urea formaldehyde, melamine formaldehyde (each of which
is an amino thermoset plastic) and acrylic (which is a
thermoplastic material). The hardness of these materials on the MOH
scale ranges from about 3.0 to 4.0. Generally, it is preferred that
any plastic particles used in the CMU mixture be of a thermoset
plastic material because these are typically harder than
thermoplastic materials, although this is not always true as
evidenced by the acrylic mentioned above. The other blasting
abrasives mentioned above include aluminum oxide, copper slag, coal
or boiler slag, glass frit, glass bead, garnet, ferric oxide
(hematite) and staurolite. The hardness of these other blasting
abrasives on the MOH scale ranges from about 5.0 to 6.0 while the
hardness of spent BAPs on the MOH scale typically ranges more
broadly from about 2.5 to 7.0.
[0017] Although lesser amounts of the spent BAPs or a BAP-PRP
combination may provide desirable characteristics to the CMU
mixture, it is preferred that the BAPs or the combination make up
at least 5% of the mixture by volume. Preferably, this amount
ranges from 5.0% to 17.0%, more preferably, from 7.0% to 16.0% and
even more preferably, from 10.0% to 16.0% or 10.0% to 15.0%. The
ratio by volume of cement to combined aggregate material and BAPs
typically ranges from 1:7 to 1:13 and often from 1:8 to 1:12. These
ranges may vary, however. Preferably, all or substantially all of
the BAPs are passable through the number 50 sieve screen with a
portion of the BAPs passing through the number 100 sieve screen
with a portion retained thereon. Preferably, the BAPs have a
fineness modulus (FM) range from 0.6 to 1.5, and more preferably
from 0.75 to 1.2.
[0018] In accordance with the invention, the CMU mixture when cured
provides several highly desirable characteristics, including
decreased water absorption, decreased water penetration and
increased net compressive strength. The cured CMU mixture meets or
exceeds all of the physical requirements established by ASTM
C-90-03. Prior art CMU mixtures have capillaries or interstitial
spaces which provide substantial porosity in the cured material.
The substantial reduction of water absorption and water penetration
in the CMU mixture of the present invention is a result of the BAPs
filling the capillaries or interstitial spaces of the cured CMU
mixture. A sufficient amount of the BAPs must be sufficiently small
to fill these capillaries or interstitial spaces to provide the
reduced water absorption and penetration. The size ranges of the
BAPs described above reflect this capability. Preferably, the CMU
mixture has an average water absorption which is no greater than
13.0 pcf (pounds per cubic foot) and is more preferably no greater
than 11.0 pcf, 10.0 pcf or 9.0 pcf. Depending upon the specific
mixture, the water absorption may be as low as a 8.0 pcf or even
lower.
[0019] The water absorption of the CMU mixture easily meets and is
typically far superior to the various ASTM C-90-03 requirements.
CMUs are typically referred to in the industry as either
lightweight, medium weight or normal weight. More particularly this
refers to the density of the CMU mixture wherein a lightweight CMU
has an average oven-dry density which is less than 105 pcf; a
medium weight CMU has an average oven-dry density ranging from 105
pcf to less than 125 pcf; and a normal weight CMU has an average
oven-dry density which is at least 125 pcf. The ASTM C-90-03
standard uses a maximum average water absorption of 18 pcf for
lightweight CMUs, 15 pcf for medium weight CMUs and 13 pcf for
normal weight CMUs. Test data showing water absorption and other
characteristics of several variations of the CMU mixture are
provided further below.
[0020] As noted in ASTM E 514-90 (Standard Test Method for Water
Penetration and Leakage Through Masonry), water penetration testing
through masonry is difficult to measure very accurately due to the
many variables which impact such water penetration and leakage.
Having said that, however, Applicant has performed tests based on
the criteria outlined in ASTM E 514-90 and has determined that the
CMU mixture of the present invention when cured far exceeds the
minimum four-hour test criteria outlined in said standard. More
particularly, a hollow CMU like CMU 10 was placed in a catch basin
above the water level within the basin. A "spray bar" saturated the
outer face of the CMU via a water pump. More particularly, the
"spray bar" included a pipe with holes drilled along one side to
allow water to flow through the pipe and out of the holes onto the
face of the block. Three tests were conducted separately on three
separate specimens for a continuous period of seven days,
twenty-four hours per day, during which no signs of water
penetration to the core of the hollow test specimens was observed.
By contrast, a prior art hollow CMU tested in the same manner
exhibited substantial water penetration to the core within a few
minutes. Thus, even given the understandable variability in sensing
water penetration and leakage, the CMU mixture of the present
invention provided a substantially minimized water penetration.
[0021] The CMU mixture when cured has an average compressive
strength which easily meets and often far exceeds the ASTM C-90-03
minimum requirement of 1,900 pounds per square inch (psi) net area,
herein referred to as the average net compressive strength.
Depending upon the particular CMU mixture, the average net
compressive strength may easily be, for example, 2,200 psi, 2,500
psi, 3,000 psi, 3,500 psi and even above 4,000 psi for certain
mixtures. This ability to produce CMUs with such substantially
increased net compressive strength values was an unexpectedly
beneficial result of the use of the BAPs in the CMU mixture. These
increased values are best explained by the BAPs within the mix
allowing for the retention of a far greater amount of water when
the mixture and water are combined and blended prior to forming CMU
10. Thus, when CMU 10 is in its plastic state, it holds a
substantially greater amount of water than a standard CMU of
comparable size. The ability of CMU 10 to retain this increased
amount of water due to the use of the BAPs was also a surprising
result and is directly related to the increased compressive
strength values. Because more water is retained due to the BAPs,
more of the cement is hydrated, which allows for the increased
compressive strength of the cured mixture. By way of example, a
mixture which is normally used to form a typical CMU without BAPs
may be adjusted in a simple manner such that fine aggregate
material within that mixture is replaced with the same or a similar
volume of the BAPs in order to substantially increase the net
compressive strength without changing the percentage of cement
within the mixture. Where the BAPs used to replace the fine
aggregate material in such an example make up approximately 10% to
15% of the CMU mixture, the average net compressive strength may
easily be increased by 400 psi to 500 psi without any additional
changes.
[0022] In addition to the improved characteristics noted above, the
CMU mixture of the present invention reduces the curing time for
CMU 10. Depending upon the locale in which a standard CMU mixture
is cured, the use of steam or a high humidity environment plus heat
maybe used to accelerate the curing process. In locales where the
humidity is sufficiently high, this may not be necessary.
Regardless of the humidity within a locale, the CMU mixture of the
present invention allows the curing to proceed at a faster rate.
This is due again to the ability of the BAPs to hold additional
water, thus adding to the water content of the CMU while
maintaining the shape and texture of the CMU, that is, without
slump. This higher water content in the CMU mixture allows the
mixture to cure more quickly, and as previously noted to have a
greater strength when cured. Because of this higher water content,
the CMU mixture of the present invention eliminates the need for
curing with water vapor or steam and the use of a kiln to heat the
CMU mixture even in locales where the humidity is not sufficiently
high enough to allow this with a standard CMU mixture.
[0023] Provided below are several examples of the composition and
characteristics of lightweight, medium weight and normal weight CMU
mixtures of the present invention. In the tables below, the BAPs
are referred to as "media".
EXAMPLE NO. 1
[0024] TABLE-US-00001 Light Weight Weight Volume % Total Cement to
Cement to Material (lbs) (cu. ft.) Volume aggregate ratio
(aggregate + media) ratio Cement 500 5.3 9.2 1:8.49 1:9.85 Fine
Aggregate 250 2.5 4.3 Coarse Aggregate 835 9.8 17.0 Light Weight
1830 32.7 56.9 Media 350 7.2 12.5 Total 3765 57.5 99.9 ASTM C-90
ASTM C-90 Net Comp. Ave. Net Comp. Std. Ave. Ave. Std. Ave. Ave.
Oven-dry CMU Strength Strength Net Comp. Absorption Absorption.
Absorption density No. (psi) (psi) Strength (psi) (lb/cu. ft.)
(lb/cu. ft.) (lb/cu. ft.) (lb/cu. ft.) 1 2579 2 2809 3 2981 2790
1900 4 11.53 11.53 18.0 95.39
EXAMPLE NO. 2
[0025] TABLE-US-00002 Medium Weight Weight Volume % Total Cement to
Cement to Material (lbs) (cu. ft.) Volume aggregate ratio
(aggregate + media) ratio Cement 500 5.3 9.9 1:7.75 1:9.11 Fine
Aggregate 2500 25.0 46.6 Coarse Aggregate 0 0.0 0.0 Light Weight
900 16.1 30.0 Media 350 7.2 13.4 Total 4250 53.6 99.9 ASTM C-90
ASTM C-90 Net Comp. Ave. Net Comp. Std. Ave. Ave. Std. Ave. Ave.
Oven-dry CMU Strength Strength Net Comp. Absorption Absorption.
Absorption density No. (psi) (psi) Strength (psi) (lb/cu. ft.)
(lb/cu. ft.) (lb/cu. ft.) (lb/cu. ft.) 1 2772 2 2761 3 2737 2757
1900 4 10.56 10.56 15.0 110.81
EXAMPLE NO. 3
[0026] TABLE-US-00003 Normal Weight Weight Volume % Total Cement to
Cement to Material (lbs) (cu. ft.) Volume aggregate ratio
(aggregate + media) ratio Cement 500 5.3 9.6 1:8.08 1:9.43 Fine
Aggregate 3635 36.4 65.8 Coarse Aggregate 545 6.4 11.6 Light Weight
0 0.0 0.0 Media 350 7.2 13.0 Total 5030 55.3 100.0 ASTM C-90 ASTM
C-90 Net Comp. Ave. Net Comp. Std. Ave. Ave. Std. Ave. Ave.
Oven-dry CMU Strength Strength Net Comp. Absorption Absorption.
Absorption density No. (psi) (psi) Strength (psi) (lb/cu. ft.)
(lb/cu. ft.) (lb/cu. ft.) (lb/cu. ft.) 1 3040 2 2877 3 3040 2986
1900 4 9.28 9.28 13.0 125.80
EXAMPLE NO. 4
[0027] TABLE-US-00004 Light Weight Weight Volume % Total Cement to
Cement to Material (lbs) (cu. ft.) Volume aggregate ratio
(aggregate + media) ratio Cement 500 5.3 8.5 1:8.89 1:10.70 Fine
Aggregate 1880 22.9 36.9 Coarse Aggregate 0 0.0 0.0 Light Weight
1280 24.2 39.0 Media 450 9.6 15.5 Total 4110 62.0 99.9 ASTM C-90
ASTM C-90 Net Comp. Ave. Net Comp. Std. Ave. Ave. Std. Ave. Ave.
Oven-dry CMU Strength Strength Net Comp. Absorption Absorption.
Absorption density No. (psi) (psi) Strength (psi) (lb/cu. ft.)
(lb/cu. ft.) (lb/cu. ft.) (lb/cu. ft.) 1 2940 2 3320 3 2910 4 3060
5 3150 3080 1900 6 9.50 7 9.20 9.35 18.0 101.25
EXAMPLE NO. 5
[0028] TABLE-US-00005 Medium Weight Weight Volume % Total Cement to
Cement to Material (lbs) (cu. ft.) Volume aggregate ratio
(aggregate + media) ratio Cement 500 5.3 8.5 1:9.00 1:10.81 Fine
Aggregate 2600 31.7 50.6 Coarse Aggregate 0 0.0 0.0 Light Weight
850 16.0 25.6 Media 450 9.6 15.3 Total 4400 62.6 100.0 ASTM C-90
ASTM C-90 Net Comp. Ave. Net Comp. Std. Ave. Ave. Std. Ave. Ave.
Oven-dry CMU Strength Strength Net Comp. Absorption Absorption.
Absorption density No. (psi) (psi) Strength (psi) (lb/cu. ft.)
(lb/cu. ft.) (lb/cu. ft.) (lb/cu. ft.) 1 4050 2 4090 3 4460 4 4240
5 4000 4170 1900 6 8.70 7 8.50 8.60 15.0 110.10
EXAMPLE NO. 6
[0029] TABLE-US-00006 Normal Weight Weight Volume % Total Cement to
Cement to Material (lbs) (cu. ft.) Volume aggregate ratio aggregate
+ media) ratio Cement 500 5.3 8.2 1:9.43 1:11.24 Fine Aggregate
4100 50.0 77.0 Coarse Aggregate 0 0.0 0.0 Light Weight 0 0.0 0.0
Media 450 9.6 14.8 Total 5050 64.9 100.0 ASTM C-90 ASTM C-90 Net
Comp. Ave. Net Comp. Std. Ave. Ave. Std. Ave. Ave. Oven-dry CMU
Strength Strength Net Comp. Absorption Absorption. Absorption
density No. (psi) (psi) Strength (psi) (lb/cu. ft.) (lb/cu. ft.)
(lb/cu. ft.) (lb/cu. ft.) 1 3330 2 3520 3 3310 4 3500 5 3360 3400
1900 6 8.86 7 9.12 9.00 13.0 126.90
[0030] Thus, the CMU mixture of the present invention and CMU 10
provide for a variety of advantages, to include a reduction in the
curing time of the CMU mixture. In addition, the mixture utilizes
spent BAPs and usually PRPs, thus recycling such BAPs and PRPs into
a highly useful product. The inclusion of BAPs in the mixture
substantially decreases water absorption of and water penetration
into CMU 10. In addition, the use of the BAPs, especially plastic
particles, decreases the weight of CMU 10 while nonetheless
increasing the net compressive strength by a substantial amount.
This decrease in weight of the CMU is advantageous in reducing the
cost of construction time due in part to the ability of masons to
lay more CMUs formed by the present CMU mixture than that of
standard CMUs which are heavier. In addition, the decreased
porosity of CMU 10 in comparison to a standard CMU reduces the
amount of paint required to paint CMU10. This also reduces the
amount of block filler used with a standard CMU when painting of
the CMU is required.
[0031] In the foregoing description, certain terms have been used
for brevity, clearness, and understanding. No unnecessary
limitations are to be implied therefrom beyond the requirement of
the prior art because such terms are used for descriptive purposes
and are intended to be broadly construed.
[0032] Moreover, the description and illustration of the invention
is an example and the invention is not limited to the exact details
shown or described.
* * * * *